The need for an intelligent private/public interface manager in a telecommunications system is continually increasing. The real impact of advanced message-based signalling systems on telecommunications networks, and subsequently on all users and system vendors, is only now becoming comprehensible.
The purpose of a Network Services Manager (NSM) is to enable a corporate telecoms manager to use his network as a strategic resource. The NSM will enable him to operate his network more effectively and efficiently, and allow the intelligent use of new public services as they materialize.
Typically, the key features of an NSM are bandwidth management, intelligent routing, service management and public network interfacing, applied to wideband traffic (up to 2 Mbit/s channels) in the first instance.
The key components of an NSM will be a Network Services Switch (NSS)--a DPNSS based switch/crossconnect, and the Network Services Management Center (NSMC).
One of the main services which may be offered by an NSM is intelligent routing. The NSMC typically will have an overview of the type of traffic (voice, video, data), the network topology, the network loading and the network facilities. It is thus able to make decisions about routing strategy in the network. Other components in the network can make decisions about routing in their own sub-networks--e.g. LAN routers in the data sub-network, iSPBXs in the voice sub-network, but only the NSM has the full picture to make the global decisions and influence the workings of the sub-networks.
Routing in the NSM would take place in the NSS. Routing in iSDX networks involves preferred outgoing link capacity checking at the originating and each intermediate node before the destination. This method tends to fill links to capacity, as alternatives are only tried when congestion is encountered. Links are segmented by Trunk Group and some are reserved for incoming only or outgoing only, to prevent either predominating excessively.
If the network is used for calls of all the same type/class, as in standard iSDX networks, then the above scheme works well. However, in the NSM scenario, it is required to distinguish between voice, data, video, and other special traffic categories (e.g. breakout, compressed voice etc.) by type/class. These have different characteristics of call hold time, BHCA, bandwidth required etc., so further optimization could occur. This is achieved by the simple process of allocating traffic characterized by long call holding times and high bandwidth requirement to the shortest route and to the private network.
To accommodate the varying demand for network bandwidth, the NSM should try to spread traffic evenly through the network so that bandwidth is available to any node that might require to increase its data bandwidth to its limit. This could be described as load balancing, and to achieve it, the NSM needs to influence the routing through the network.